I would not say never; there may be times when the pipe requires a tapered stem, i.e. a Canadian shape, or, in the case of a pipe I own, one that needs a very short stem (a Lane-stamped Executive freehand, deeply bent with long stank, and a one-inch stem...not "room" for a DC or saddle stem. I honestly don't know if this a Reuben era or not, but I assume it's later). The Authentic was one of the machine made series of pipes, like Belvedere, Special, Perfection and Relief and thus did not bear the MADE BY HAND (or similar nomenclature) that the hand-made lines did (Freehand Relief, Distinction, Executive, Selected, et al). You can check this out for yourself by examining the descriptions of Charatans on Smoking Pipes.com, which will bear this out. And again, the numbering system of pipes from the 50's, 60's and 70's were, as far as I know, all 2-3-and four digit numbers: I imagine when Dunhill bought the company they changed the numbers (as they did with their own pipes around the same time).
A lot of the Charatan articles contradict each other and will leave you lip-diddling. And I will say that I am by no means an expert on Charatan and you should take my comments with a big grain of salt. I hope someone who knows more than I do will jump in a correct any errors here.
